The purpose of this research is to understand the structure formation and function of subcellular organelles. Using bacterial flagella as relatively accessible and simple models to gain insights into the following: 1. Protein structure and function: A. Monomeric flagellin-chemistry, structure, stability, immunological properties; B. Polymeric flagellin-nature of flagellin-flagellin interactions; relationship of monomer conformation to properties of the organelles; immunological properties; C. Flagellar hook- chemistry, nature of subunits, stability, function; D. Basal structure- chemistry of discs and connecting rod; nature of attachment to cell wall and membranes. 2. Synthesis of flagellar components and their assembly into the flagellum; sequence and regulation of the assembly process. 3. Flagellar architecture and function: A. Structure and function of flagellar filaments, hooks and basal structures; B. Nature of motility; transformation of chemical to kinetic energy; role of cell surface structures in motility; regulation and coordination of flagellar activity. 4. Nature of stability of thermophile flagellins and flagella; nature of intra- and intermolecular interactions; nature of interactions pertinent to stability.